Magnetic elements such as transformers and inductors are widely used in many electronic devices to generate induced magnetic fluxes. For example, the transformer is a magnetic element that transfers electric energy from one circuit to another through coils in order to regulate the voltage to a desired range required for powering the electronic device. In addition, the inductor is usually electrically connected with the transformer for filtering signals.
FIG. 1 schematically illustrates a transformer and an inductor on a system board according to the prior art. As shown in FIG. 1, a first transformer 11, a second transformer 12 and an inductor 14 are disposed on a system board 10. In particular, the first transformer 11 and the second transformer 12 are disposed on a circuit board 13, and the circuit board 13 is inserted into the system board 10. In addition, the inductor 14 is directly mounted on the system board 10. Moreover, the first transformer 11, the second transformer 12 and the inductor 14 are electrically connected with each other through electrical traces (not shown). Consequently, the current outputted from the secondary side of the first transformer 11 and the current outputted from the secondary side of the second transformer 12 are transmitted to the system board 10 through the circuit board 13. After the currents are collected by the system board 10 and transmitted to the inductor 14, the output current is filtered by the inductor 14 and outputted to a load (not shown).
However, the layout structures of the above magnetic elements still have some drawbacks. Firstly, since the first transformer 11, the second transformer 12 and the inductor 14 are separately disposed on the system board 10, these magnetic elements occupy much layout space of the system board 10. The layout structures of the above magnetic elements are detrimental to the miniaturization and high power development of the electronic device. In other words, it is important to increase the space utilization and the component integration of the system board 10. Secondly, the layout structures of the above magnetic elements result in inconsistent current paths. That is, the current path from the secondary side of the second transformer 12 to the inductor 14 through the circuit board 13 and the system board 10 is longer than the current path from the secondary side of the first transformer 11 to the inductor 14 through the circuit board 13 and the system board 10. Due to the inconsistent current paths, the current outputted from the first transformer 11 and the current outputted from the second transformer 12 are unbalanced. Consequently, it is difficult to control the circuitry. Thirdly, since the current paths from the secondary sides of the first transformer 11 and the second transformer 12 to the inductor 14 through the circuit board 13 and the system board 10 are very long, the impedance value is very large. Under this circumstance, the power loss is increased. Moreover, since the currents from the first transformer 11 and the second transformer 12 are collected to the system board 10, the temperature of the system board 10 is too high.
Therefore, there is a need of providing an integrated magnetic module in order to overcome the above drawbacks.